https://github.com/phstc/spelling-corrector

It's a Ruby implementation of Norvig Spelling Corrector plus Levenshtein distance fallback.
https://github.com/phstc/spelling-corrector

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It's a Ruby implementation of Norvig Spelling Corrector plus Levenshtein distance fallback.

• Host: GitHub
• URL: https://github.com/phstc/spelling-corrector
• Owner: phstc
• Created: 2013-03-16T20:21:21.000Z (over 11 years ago)
• Default Branch: master
• Last Pushed: 2013-03-26T14:27:00.000Z (over 11 years ago)
• Last Synced: 2024-04-15T02:13:45.893Z (7 months ago)
• Language: Ruby
• Homepage:
• Size: 3.77 MB
• Stars: 6
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Spelling Corrector

It's a Ruby implementation of [Norvig Spelling Corrector](http://norvig.com/spell-correct.html) plus [Levenshtein distance](http://en.wikipedia.org/wiki/Levenshtein_distance) fallback.

If Norvig algorithm doesn't find the correction, this implementation will look for the first occurrence (distance <= 8) of a similar word using Levenshtein distance.

```ruby

known([word]) || known(edits1(word)) || known_edits2(word) || levenshtein(word) || ["NO SUGGESTION"]

```

Levenshtein costs: ins=2, del=2 and sub=1.

## The Algorithm

Firstly, I recommend to read the [Norvig explanation](http://norvig.com/spell-correct.html) and [Levenshtein distance](http://en.wikipedia.org/wiki/Levenshtein_distance) then have a look at the tests (specs directory), they show how each method work, it helps the understading of the algorithm.

Most of the `SpellingCorrector` methods, should be private, I left them as public only to document (explain) them with tests.

## How to use it

```ruby

require "lib/spelling_corrector"

corrector = SpellingCorrector.new

corrector.correct "cen" => "can"

corrector.correct "unknownword" => "NO SUGGESTION"

```

### Persisted Spelling Corrector

The `PersistedSpellingCorrector` and `PersistedWordCollection` are implementions using MongoDB (encapsulating the non-persisted implementations) to persisted the corrections and trained word collection.

## Examples

In the `examples` directory, there are two examples, one using refinements and another with [Sinatra](http://www.sinatrarb.com/) to expose Spelling Corrector as an API.

### Refinements

If you are using Ruby 2.0.0 we can use refine your string classes using the Spelling Corrector.

```ruby

# examples/refinement_spelling_corrector.rb

using StringSpellingCorrectorRefinement

puts "cen".correct

```

### webapp

The webapp example is deployed at Heroku, you can easily test it via `curl` or directly in the browser (shame on you).

```bash

curl spelling-corrector.herokuapp.com/correct/cen

=> can

```

Since it uses PersistedSpellingCorrector, to run it locally, you will need a MongoDB connection.

## License

This code is licensed under:

MIT License GPL